CA1312502C - Dock seal - Google Patents

Abstract

ABSTRACT
An inflatable dock seal for mounting about a loading dock opening to provide a cushioned seal against a vehicle has an upper hollow inflatable curtain and a pair of vertical inflatable side members; the side members inflate laterally of the opening directly towards each other along a phantom axis of inflation which is perpendicular to a phantom axis of entry of the opening; the upper hollow inflatable member is located in opposed spaced apart relationship with a rear end of a support structure, and the pair of vertical hollow inflatable members is located in opposed spaced apart relationship with the rear end of the support structure, the vertical inflatable members are in facing spaced apart relationship and are inflatable directly towards each other, laterally of the opening along a phantom axial line of inflation generally perpendicular to the phantom axis of entry, the facing spaced apart relationship of the vertical inflatable members is maintained throughout inflation along the phantom axial line of inflation, and the opposed spaced apart relationship of the inflatable seal and the rear end of the support structure is maintained throughout inflation of the inflatable seal, an air vent in the inflatable seal permits constant exit of air under pressure from the inflatable seal, whereby the inflatable seal is yieldable.

Description

This invention relates to a dock seal device Eor loading dock openings in a wall and to seal ele~en-ts oE such a device, more especially the invention is concerned with an inflatable dock seal device and inila-table dock seal elements.
; The present appliGation is a division of Application No. 537,937, filed May 25, 1987.

Inflatable dock seals are known from U.S.
Patents 3,303,615; 3,714,745 (Canadian ~atent 958,946);
3,391,502 (Canadian Patent ~4~,999) and 3,391,503 (Canadian Pa~tent ~ 77) all of Larry O'Neal, an~
from U.S. Patent 3,994,103 (Canadian Patent 1,079,125) of Wilfred Ouellet. These generally comprise a top, hollow, ~lexible, inflatable, hori70rltal section and a pair of side, hollow, inflatable~ vertical sections arranged about a loading dock opening.
These sections may constitute three separate members independently mounted about the opening with -their interiors in air f]ow communication as described in U.S. Patent 3,714,745 or they may cons-titute a single generally U-shaped member as shown in U.S. Patents 3,303,615; 3,391,5Q2; 3,391,503 and 3,994,103.
The dock seal devices serve to seal the loading area in which personnel operate Erom the external environment so that personnel are sheltered during poor weather. In additlon the seal devices serve to prevent loss of heat from a heated building to a cold environment, and access to the bui.lding of cold air during winter, and conversely to prevent access of hot humid air to a cooled or air-conditioned building during summer.
Dock seals o.E the general type comprising separate members, such as shown in in U.S. Patent _ 3,714,74~, have the advantage that the members can be spaced, at the time oE installation, about the dock opening, so that they do not interfere or intrude into the entry passage in front of the openiny, i.nto and out of which a truck is to be brought into register for loading and unloading, and additionally they can be more readily adapted to different size openings.
As can be seen from FIGS. 3 and 4 in U.S.
Patent 3,714,745, the vertical side members inflate ~ 20 along an arcuate path or, otherwise stated, have an : arcuate axis of inflation, whereby in the non-inflated or collapsed configuration shown in FIG. 3 of the Patent, the col].apsed, vertical, side members are retracted away from the dock opening; and in the inflated configuratlon shown in FIG. 4, the free ~3~?5~

outer ends of the side members, which engage the truck, are spaced forwardly of the doclc opening so as not to inter~ere or intrude into the loading area where thère is a risk of damage to the flexible members such as by fork lift trucks operatiny in the loading area.
isadvantages oE dock seals of the general type shown in U.S. Patent 3,391,503 are that the arcuate, inflated side members become floppy with increasing arcuate length and for practical purposes the arcua-te length cannot exceed about 2 ft. Further-more the gap between the arcuately inflated members and the wall o:E the opening produces an open bottom which reduces the sealing efficiency and permits access of heated air from the building to the at~osphere, and en-try of cold air, in win-ter, or access of warm external air to a cooled environment within the building in summer. Loose flaps of sheet material are sometimes provided to bridge the gap 2~ and which must be manually fastened and unfastened before and after use to the wall, however, personnel tend to ignore them because of the inconvenience involved in assembling the flaps.
disadvantage shared by all oE the dock seals of the afore-mentioned Patents is that in seal-7 3 1 ~5~
fi i.ng the opening they exclude natural light so that the loading area is oEten only dimly lit by artiEicial lights within the building which are often remotely spaced Erom the opening so that lightiny is inadequate and the working environment uncomfor*able.
~nother disadvantage shared by all dock seal devices of the afore-mentioned Patents is that they have not addressed the problem of rain water or the like seeping between the horizontal seal section and the truck, into the loading area.
In the seal device Oe ~.s. Patent 3,71g,745, the roo~ oE the upper support is flat and inclined downwardly towards the truck as can be seen Erom FIGS. 2 and 5 of that Patent. Thus rain water flows Erom the flat rooE onto the roof and sides of the truck and may seep between the truck and the seal members, particularly with movement of the truck to adjust its position.
In the seal devices of the other Patents, ~or example, U.S. Patent 3,391,503 it can be seen that rain water will flow downwardly over the convex surface of the horizontal section.
The present invention seeks to provide a dock seal device overcoming the afore-mentioned disadvantages.

_ 5 _ ~3~2~02 In one aspect the invention provides a dock seal device in which the inflatable members can be readily spaced about openings of different sizes and in which the vertical members have a greater axial length of inflation than previously possible.
In particular, the inflatable members include an upper inflatable member and a pair of vertical inflatable members which are adapted to be maintained in opposed spaced apart relationship with a wall face of a building wall on which the dock seal device is mounted, throughout inflation of the device. In this way a gap is maintained between the vertical inflatable members and the wall face.
The dock seal device has an air ven-t which permlts constant exit of air under pressure from the device, whereby the device is yieldable.
The invention also provides a dock seal device and dock seal elements having an inflatable bottom seal to bridge the lower gap between the building wall and the vertical members.

,,~ ''.1~

Still further the inventi,on provides a dock seal device in which the vertical, inflatable side members are spaced from the wall permitting access of natural light to the loading area.
Another aspect of the invention resides in a dock seal device in which rain water and the like is directed laterally away from the loading area.
In accordance with the invention an infla-table dock seal is provided for positioning about an opening in a wall. The seal has an upper, inflatable member and a pair of inflatable side members in opposed, spaced apart relationship. The side members each havç outer and inner ends in facing relationship r which faclng relationship is maintained throughout inElation of the side members.
Thus, in particular, the side members inflate laterally of the openiny about which they are mounted, directly towards each other, and their respective inner and outer ends are all maintained in opposed facing rela-tionship during inflation.
In other words the opening has a phantom axis of entry generally perpendicular -to the Eace of the wall and the side members inflate along a phantom axis of infla-tion perpendicular to the phantom axis of entry.
In a further aspect of the invention there is provided a dock seal element which may form an inflatable side member of the seal; the element com-prising an inflatable seal member of generally L-shaped configuration having an elongate, inflatable leg portion and a short, inflatable foot portion.
An inlet means in the member permits entry of inflat-ing gas. The leg portion and the foot portion havea major axis or direction of inflation, la-terally of the L-shape.

The invention is illustrated in a particular and preferred embodiment by reference to the accom-; panying drawings in which:

- 1 3 ~ ~5~

FIG. l i.s a perspective view of an inflated dock seal device of the invention mounted about a loadi.ng dock opening in a wall;
FIG. 2 is a schematic sectional plan view of the lower hal:E of the device of FIG. 1 is a non-inflated confi~uration;
FIG. 3 is a schematic sectional plan view of the lower half of the device of FIG. 1 in an inflated configuration;
r~lG. ~ is an exploded perspective view of the device of FIG. l;
E'IG. 5 is a front elevation of the device vf FIG. l;
FIG. 6 is a perspective view of a vertical inflatable seal member of the dock :~ seal device of the invention; and FIG. 7 is a perspective view similar to FIG. 6 but showing the interior of the seal.

With further reference to FIG. 1, a dock : seal device 10 is mounted in an opening 12 of a wall 14 having a wall face 16. Opening 12 has a phantom axis of entry 18 being the central line along which a truck to be loaded or unloaded will travel into or out oE the loading area of the openi.ng 12.

g il~

Bumper guards 19 are mounted on wall 14 below devlce 10.
Device lO comprises an upper, generally horizonta~ inflatable drop curtain 20 and generally L-shaped vertical infla-table side members 22 and 24.
It can be seen from FIG. l that members 22 and 24 are in opposed Eacing relationship adjacent the side edges of opening 12, and curtain 20 extends in front of the upper ends of members 22 and 24 and across the upper end of opening 12.
Device 10 Eurther includes an upper support housing 26 in which is housed the upper end of curtain 20; and a pair of side supports 2~ which support members 22 and 24. It will be understood that housing 26 and side supports 28 are secured to wall 14 by anyconvenient means, for example, screws (not shown).
Curtain 20 includes a plurality of balloon portions 30 s~parated by internal apertured panels 32, the latter being more particularly shown in FIG.
4.
The L-shaped members 22 and 24 comprise a generally vertical leg portion 33 and a generally horizontal Eoot portion 35, both being inflatable.
The leg portions 33 comprise balloon portions 34 separated by internal mesh panels 36, the latter lo- 13~25~2 beiny seen in FIGS. 2, 3 and 4.
The L-shaped members have their major axis - 37 of inflation extending laterally of the L-shape so that the'L-shape expands or inflates laterally.
Phantom axis of in~lation 37 is perpendicular to phantom axis of entry 18.
With particular reference to FIG. 4, sup-port housing 26 includes a front wall 38, a rear wall 40 and a roof 42, the roof ~2 haviny inclined portions 44 which are inclined downward].y from a generally Elat top portion 45. Side walls 46 extend between front wall 38 and rear wall 40, each side wall 46 having a slide groove 48. Elousing 26 defines an internal cavity 50.
The side supports 28 each comprise a lattice frame 52 having a plurality o~ large openings 54 defined between horizontal laths 56 and front and rear vertical studs 58a and 58b, respectively. A
clear side panel 60 suitably of translucent plastic sheeting is secured to the outer face of each lattice frame 52 and a clear slip panel 62, suitably of P.V.C. is secured at an outer elongated edge to each stud 58a, whereby the panels 62 extend laterally of the openi.ng 12 generally -towards each other and extend freely at their inner ends.

Trim 63 suitably of P.V.C. covers the joint between each panel 62 and its stud 58a.
Drop cur-tain 20 hangs generally vertieally from a curtain support 64. Slide mounts 66 on ~ curtain support 64 engage slide grooves 48, to mount : eurtain support 64 with drop curtain 20 in housing 26.
A cylinder 90 houses a torsion spring 70 and is mounted between a pair of torsion spri.ng mounts 68 on curtain support 64, the cylinder 90 being mounted for rotary rnovement in spring moun-ts 68.
. A plurality of retraction straps 72 are secured at one end to cylinder 90, and at a remote end to an internal portion of drop curtain 20, espeeially an internal por~ion of curtain 20 remote ~rom support 64.
A mo-tor or air compressor 76 adapted to pro-vide air under pressure is mounted within housing 26 for flow oE air under pressure through an air duct .-74 eommunicating with the interior of eurtain 20.
Air duc-ts 78 extend through support 64 to ; the interior of curtain 20 and are eonneeted to air ducts 80 which eommunicate with the interior of vertical inflatable members 22 and 24. In this way the interior of inflatable drop eurtain 20 and of the separately formed inflatable members 22 and 24 are all in air flow eommuniea-tion with air under pressure delivered from mo-tor 76.

13125~2 ~ small air vent 82 is provided in drop curtain 20.
Retractors 84, ~or example, of elastic or other material having a memory are supported a-t the upper and lower ends o~ Erame 52 and are connected to vertical inElatable members 22 and 24. In parti-cular the retractors 84 may each comprise an arm mounted to frame 52 and an elastic cord Eor connec-tion to.a vertical member 22, 24~
With further re~erence to FIGS. 6 and 7, vertical in~latable member 22 has upper and lower retraction systems 92 and 9~ in leg 33 and an elastic foo-t retraction system 96 in Eoot 35.
: Upper retraction system 92 includes a pocket 98 on leg wall 95 housing a counterweight 100, pulleys I02 and 104 mounted on leg wall 95, guide loops 106 ad~acent pocket 98 on leg wall 95, and cords 108 and 110.
Cord 108 is connected at one end to counter-weight 100, passes over pulley 102 through guide loops 106 and is secured at its other end to leg wall 97.
Cord 110 is connected at one end to counter-weight 100, passes over pulley 104 and is secured at its other end to leg wal.l 97.
Lower retraction system 94 is essentially identical to system 92 and mounted in the~same manner.

1 3~ ~502 Elastic retraction system 96 comprises elastic cords 112 and 114 connected at their free ends between side walls 99 and 101 oE foot 35~
ela.stic cords 116 and 118 connected between upper and lower walls 103 and 105, respectively, of foot 35, and elastic cord 12~ connected between side wall 101 and upper wall 103.
` Bumper guards 19 include front cushioning pads 86.
During periods when no loading or unloading is taking place through opening 12, the opening 12 is closed by a conventional door 88. In this condition the seal device 10 is in a non-inflated, retrac-ted conditionin which rotation oE cylinder 90 has caused retraction straps 72 to wind thereon thereby lifting the folds of material which form drop curtain 20.
The upper and lower retractors 84 draw the folds of material of members 22 and 24 towards the lattice frames 52. At the same time, counterweights 100 of retraction systems 92 and 94 draw in the collapsed material of leg 33 and elastic retraction system 96 draws in the collapsed material oE Eoot 35. In this way, the material of the members ~2 and 24 is essen-tial.ly contained in the space defined between the lattice frame 52, slip panels 62 and the wall face 16, as more par-ticularly shown in FIG 2. When retraction sys-tem 96 is employed lower retractor 84 may be dispensed with and vice-versa.

-` 131~502 When loading and unloading is to occur, the drop curtain 20 and members 22 and 24 are inflatecl by continuous flow of ai.r from motor 76 through air duct 7~ to the interior of curtain 20 and thence through air ducts 78 and 80 to the interior of members 22 and 24.
constant flow of air into the interior of the device in this way, under sliyht pressure, is sufficient to overcome -the spring pressure of torsion spring 70 so that cylinder 90 is unwound by the downward movement of curtain 20 during inEla-tion, which draws with it straps 72. Similarly the air pressure in inElatable members 22 and 24 during inflation overcomes the retracting force of re-tractors ~4.
In like manner the air pressure in members 22 and 24 during inflation overcomes the elastic re-tracting force of elastic retraction system 96 as : well as the weight retracting force of counterweight 100 of retraction systems 92 and 94.
The air vent ~2 permits constant exit of air under pressure from the system whereby a constant flow of air under pressure is introduced by motor 76.
The inflatable curtain 20 and the inflatable members 22 and 24 formed of flexible fabric or mate-rial which is air impervious, tear resistant and cap-able of repeated engagement with vehicles without damage. Suitable materials are vinyl coated nylon, for example, neoprene coated nylon.
In operation, motor 76 provides a constant " 1312502 Elow of air under pressure maintaining curtain 20 and members 22 and 24 inflated but yieldable. The system is not air-tight, since air escapes continuously from vent 82, so that the curtain 20 and members 22 and 24 are yieldable and are readily deformed responsive to movement of a vehicle to form a pliant, cushioning seal around the vehicle.
When the inflated curtain 20 and members 22, 24 are to be collapsed, motor 76 is switched off ; 1~ and the air escapes through duct 78 and vent 82 under the re-tractiny Eorce oE retractors 84 and torsion spring 70.
A particular feature of the present invention is that ver-tical inflatable members 22 and 24 inflate laterally oE the opening 12 directly towards each o-ther and thus in a direction generally perpendicular to phantom axis of entry 18. In this way the device 10 can be constructed such that the .inflatable members 22 and 24 have a lateral inflat-able length as much as four or five feet which is in rnarked contrast to the two feet maximum possible with conventional seals which inflate along an arcuate path.
Thus the device 10 of the invention can readily be adapted to openings 12 of various widths.
Another feature of the invention resides in the foot portion 35 which bridges the space between the vertical rnernbers 22 and 24 and the opposed wall face 16, thereby providing an inflated bottom seal improving the overall efficiency o.E the clevice 10.
In conventional sealing devices in which the vertical members inElate along an arcuate path, there is no inflated bottom seal, and the space is either open permltting entry or exit of warm air, or hang-lng flaps of sheet material are employed to bridge the gap and which must be secured to the wall face 16. In practice, personnel tend to ignore the use of the flaps even when provided, in view oE the incon-venience of installation necessary, so that undesired heat loos or heat entry occurs, thereby reducing the efficiency of the system.
Another advantage providecl by the present invention resides in the use of the clear side panels 16 in conjunction with the lattice frame 52 having large openings 54. This permits entry of natural light into the opening 12 which would be dark in the absence of adequate artificial lighting. Further-more, the entry of natural light provides a more com-fortable, less claustrophobic working environment.
Still another advantage resides in the clear slip panels 62 which may flex about the joint with stud 58a. The slip panels 62 serve to protect the members 22 and 24 against damac3e from a truck wh:ich may approach the opening 12 in a misaligned con-figuration. In such situation the protect.ive slip panel 62 will flex and the truck will slide against it withoutdamaging the vertical member 22 or 24.
Still another advantage o~ the device lO of the invention resides in the rooE ~2 having inclined portions 4~ which permit flow of water, snow and ice outwardly and away Erom -the fron-t of device lO where the truck is to be located and where unloading and loading operations are to be conducted. Conventional roofs oE dock seal clevices are Elat and slope for-wardly downwardly away from the wall so that such ; water flows to the front of the dock seal device and on to the rooE of a truck, if present, from where it : may flow over the sides and seep between the outer : . truck walls and the inflated members.
; It will be noted that in FIGS. l and 5 the opening 12 is seen closed by a door; this door i5, of course, raised during loading and unloading.

Claims

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. For use with a dock seal device for posi-tioning about an opening in a wall face, which opening has a phantom axis of entry extending through the opening generally perpendicularly of the wall face, and a support structure having a rear end adapted to be positioned on the wall face about the opening such that said support structure projects forwardly of the wall face to a front end spaced apart from the wall face, the improvement being an inflatable seal supported by said support structure, said inflatable seal comprising:
an upper hollow inflatable member, inflat-able by air under pressure, for location in opposed spaced apart relationship with the rear end of the support structure, and a pair of vertical hollow inflatable members, inflatable by air under pressure, for location in opposed spaced apart relationship with the rear end of the support structure, said vertical inflatable members being in facing spaced apart relationship and being inflatable directly towards each other, laterally of the opening along a phantom axial line of inflation generally perpendicular to the phantom axis of entry, said facing spaced apart relationship of said vertical inflatable members being maintained throughout inflation along said phantom axial line of inflation, and said opposed spaced apart relationship of said inflatable seal and the rear end of the support structure being maintainable throughout inflation of the inflatable seal, and an air vent in said inflatable seal per-mitting constant exit of air under pressure from said inflatable seal, whereby said inflatable seal is yieldable.

2. An inflatable seal according to claim 1, wherein said upper inflatable member comprises a horizontal inflatable drop curtain, said inflatable drop curtain and said vertical inflatable members being separately formed and including air ducts connecting the interior of said inflatable drop curtain with the interiors of the vertical inflatable members.

3. An inflatable seal according to claim 2, wherein each of said vertical inflatable members has opposed first and second side walls in facing relationship, said facing relationship of said first and second side walls being maintained throughout inflation of said inflatable vertical members, and at least one retraction system housed in each inflatable vertical member comprising a counter-weight disposed adjacent said first side wall, first and second adjacent pulleys supported on said first side wall, vertically above said counterweight; a first elastic cord extending elastically from said counterweight over said first pulley to said second side wall, and a second elastic cord extending elastically from said counterweight over said second pulley and being guided along said first wall to a position below said counterweight and thence to said second side wall.

4. An inflatable seal according to claim 1, wherein said vertical inflatable members each have an upright elongate inflatable leg portion extending generally downwardly of said upper inflatable member, and a short inflatable foot portion extending generally perpendicularly of a lower end of said leg portion, remote from said upper inflatable member.

5. An inflatable seal according to claim 4, wherein said vertical inflatable members each have a front face and the foot portions extending generally rearwardly, perpendicularly of the front faces so as to extend from said front faces towards the opening in the wall face.

6. An inflatable seal according to claim 5, wherein each of the foot portions has an outer side face and an inner side face in facing relationship with each other, said facing relationship being maintained throughout inflation of each said vertical inflatable member.

7. An inflatable seal according to claim 6, wherein said inner and outer side faces of said foot portions are all maintained in opposed facing relationship throughout inflation of said vertical inflatable members, said side faces of said foot portions extending directly towards each other during inflation.

8. An inflatable dock seal for positioning about an opening in a wall, said seal comprising:
an upper horizontal inflatable member, first and second vertical inflatable side members in opposed spaced apart relationship, said first and second vertical side members each being of generally L-shaped configuration having an upright elongate inflatable leg portion extending generally downwardly of said horizontal member, each leg portion terminating at a lower end remotely spaced from said horizontal member in a short inflatable foot portion extending generally perpen-dicularly of said leg portion, said first and second vertical side members each having a front face with said foot portions extending generally rearwardly, perpendicularly of the front faces so as to extend from said front faces towards the opening in the wall, each foot portion having an outer side face and an inner side face in facing relationship with each other, said facing relationship being maintained throughout inflation of each said vertical member, and an air vent in said dock seal permitting constant exit of air under pressure from said dock seal, whereby said dock seal is yieldable.

9. A dock seal according to claim 8, wherein said inner and outer side faces of said foot portions are all maintained in opposed facing relationship throughout inflation of said vertical side members, said outer side faces of said foot portions extending directly towards each other during inflation.

10. A dock seal according to claim 8, wherein said foot portions have upper and lower opposed foot walls extending perpendicularly, rearwardly of the front faces, said foot portions each having an elastic foot retraction system comprising elastic foot cords elastically extending between said outer and inner side faces and elastic foot cords elastically exten-ding between said upper and lower foot walls.

11. A dock seal according to claim 10, wherein said leg portions have opposed first and second side walls extending generally perpendicularly of the front faces, at least one leg retraction system housed in each of said leg portions, comprising a counter-weight disposed adjacent said first side wall, first and second adjacent pulleys supported on said first side wall, vertically above said counterweight; a first elastic leg cord extending elastically from said counterweight over said first pulley to said second side wall, and a second elastic leg cord extending elastically from said counterweight over said second pulley and being guided along said first wall to a position below said counterweight and thence to said second side wall.

12. A dock seal according to claim 11, wherein said at least one leg retraction system comprises upper and lower leg retraction systems.

13. An inflatable seal according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, wherein said upper inflatable member and said vertical inflatable members are formed of air impervious, tear resistant, flexible material.

14. An inflatable seal according to claim 2, including an air duct for feeding air under pressure to the interior of said horizontal inflatable drop curtain, and said air vent being in said drop cur-tain.

15. An inflatable seal according to claim 4, 5, 6 or 7, wherein said upper inflatable member com-prises a horizontal inflatable drop curtain, said inflatable drop curtain and said vertical inflatable members being separately formed and including air ducts connecting the interior of said inflatable drop curtain with the interiors of the vertical inflatable members and including an air duct for feeding air under pressure to the interior of said horizontal inflatable drop curtain, and said air vent being in said drop curtain.

16. A dock seal according to claim 8, 9, 10, 11 or 12, wherein said upper horizontal, inflatable member comprises a horizontal inflatable drop cur-tain, said inflatable drop curtain and said vertical side members being separately formed and including air ducts connecting the interior of said inflatable drop curtain with the interiors of the vertical side members, said air vent being in said drop curtain.